Valve-gear for engines.



PATBNTED APR. 2.6, 1904.

40. JACKSON. VALVE GEAR FUR ENGINES.

APPLIGATION FILED MAY 14, 1902.

N0 MODEL.

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UNITED STATES Patented April 26, 1904:.

PATENT OEEICE.

VALVE-GEAR FOR ENGINES.

I SPECIFICATION forming part of Letters Patent No. 758,317, dated. April26, 1904.

Application le May 14, 1902. A Serial No. 107,280. (No model.)

To all whom t may concern:

Be it known that I, OswALD JACKSON, residing at Carrollton, in thecounty of Greene and State of Illinois, have invented a new and risefulImprovement in Valve-Gear for Engines, of which the following is adescription, reference being had to the accompanying drawings,

which are a part of this specification.

My invention has relation to improvements in valve-gear for engines.

of machinery that that engine, other things being equal, which mostnearly obtains the that a full head of steam is admitted at once againstthe end of the piston, thus doing away `with the gradual admission ofsteam, technic# allyiknown as wire-drawn steam, my improved constructionalso being such that the steam is fully exhausted, whereby the backpressure existing in the cylinders of ordinary- -engines is obviated.

A Jfurther important object accomplished by my invention is -the doingaway with a number 1of wearing parts necessary in the ordinarylocomotive valve-gear.

In the accompanying a side elevation of the invention. Fig. 2 is a planview thereof. Fig. 3 is a side elevation of the pivoted slotted plate,and Fig. 4: is a cross-section on the line 4 i of Fig. 3.

The frame of the engine may be of any desirable construction bestadapted for supporting the operative parts of the invention.

vIn the accompanying drawings I show abed 5, on which the differentparts are supported and carried. At one end of the bed-is an upwardextension 6, on which is supported a valve-casing 7, in which steam isadmitted in any desirable manner, preferably from the top through asteam inlet-pipe 8. The steam is exhausted from the valve-casing throughan exhaust-pipe 9, preferably extending from It isa well-known, -factamong those skilled in this particular line drawings, Figure 1 is oneend of said casing. Within the chamber of the valve-casing is adapted toreciprocate a valve 10, having centrally therearound an annularsteam-channel 11. Leading from the valve-chamber and extendingto thecylinder 12 are the usual channels 13 and 14. The valve is providedcentrally therethrough and from end to endv thereof with a channel 15.y

In the position of the valve shown in Fig. 2 the annular channel 11 isin registration with the channel 13, and consequently theinletsteamadmitted to the channel 11 from' the pipe 8 is free to pass by way ofchannel 13 into the cylinder 12 andthere act against the piston 16 insaid cylinder. The vsteam in advance of the piston is free to exhaust byway of the channel 14. into the valve chamber,

lthence through the longitudinal channel 15 of the valve to theexhaust-pipe 9. Extending from the valve and through one end of thevalve-casing is a valve-rod 17. To one end of this valve-rod isconnected the upper end ofv a crank-arm 18, said crank-arm extendingfrom one end of a rock-shaft 19, said rock-shaft having its bearing inan opening in the upward extension 6. The opposite end of saidrock-shaft has secured thereto and depending therefrom a crankfarm 20,and the lower end `of this arm has pivoted thereto a link or lever 2l.The rear end of this link extends in between the side members of a plate22 and is provided with a lateral pin 23, on which is mounted a roller24, said roller riding in an elongated slot 25, (preferably struck inthe arc of a circle,) formed in one of the side members of said plate22. The plate 22, which in `this art is termed a link, is pivoted on apin 26, projectinglaterally from an upward extension 27 of thebed-plate. Projecting from the lower end of the plate 22 isa stud 28,said stud having mounted .thereon a roller 29, which is adapte-d to workin a cam-groove formedon a disk 30. This disk is mounted fast on thecrank-shaft 31 of the engine, said crank-shaft being mounted inupwardly-extending bearings 32 32. It will be noticed that the portionof the cam-groove .from the points al) is in the form of an arc of atrue circle, the portions from c c andV h Z are irregular in shape orout of true circular form,.

IOO

`34 which extends from the piston of the cylinder.

The numeral 35 indicates a medially-pivotl* ed reversing-lever, thepivot thereof being at the point 36. This lever has pivoted thereto nearits outer end a spring-controlled linger 37, which is adapted to operateadog 38, said dog working over the curved edge of anotched bar 39. Theend of the short arm of the lever 35 is connected to the link 21 bymeans of links 40. A

The upward extensions 6 and 27 of the bedplate constitute a singlevertical wall, to which the valve-casing "7 is vsecured and in which therock-shaft 19 and the pivot-pins 36 and 26 are mounted, and forming abearing for the ycrank-shaft 31 and a support for the notched bar 39.

In the operation of the mechanism when the shaft 31 is revolved the disk30 is of course revolved therewith. In the revolutiony of this disk whenone of the portions a to c or ,Zito CZ of the cam-groove is brought intoengagement with the roller 29 the medially-pivoted plate 22 is of courseactuated, and inasmuch as the roller 24, carried by the pin 23 of thelink 2l, rides in the slot 25 of this pivoted plate said link is alsoactuated. i

This actuation of the link will, through the crank-arm 20, cause aturning of the rockshaft 19 and also a Iturning of the crank-arm 18 onthe opposite end of said rock-shaft, and:

hence the valve 10 is moved in a'direction to v fully open the inlet orfully open the exhaust,

in accordance with which of the channels 13 0r 14 is acting as the inletor as the exhaust. At this time the roller 29 will have passed from theirregular' portion ce to c o1 to d and on to the true circular portionof said groove between the points o and I), and while said true circularportion of the groove re-A mains in engagement with the roller theadmission and exhaust channels are maintained open to their full extent.By this arrangement a full head of steam is admitted at once against theend of the piston, and an instan-v taneous and full exhaust is alsoprovided, the exhaust starting a little prior to the admission of theinlet-steam. Heretofore the admission of the inlet-steam and the exhaustof the exhaust-steam has been gradual, and by the time the inlet-port isopen fully the valve is commencing to close said port. In my improvedconstruction the inlet and exhaust ports, as stated, are openedinstantly and remain open for a short period of time in order that thepiston may derive the benefit of the full head of steam, and at the sametime the exhaust-steam in advance of the piston is exhausted, therebyobviating the back pressure existing in cylinders of the ordinary formof engines. It will also be apparent that in my form of valve-gearduring this period of inaction of thevalve the parts are not subject-Attention is directed to the fact that there A is a small portion of thecam-groove between the points c and d, and connecting the irregularportions of said grooves, which is also on a true circle, andconsequently when the roller is on this smaller true circle the valve isalso inactive. Again, when the valve is in motion there is of course ashort period of time when both the inlet and exhaust channels are closedby said valve. During this brief period the piston 16 is actuated by theexpansion of the steam in the cylinder.

While I prefer to construct the cam-groove as illustrated in thedrawings,yet I do not wish to limit myself specifically thereto,inasmuch as said groove may be of any shape which will effect thecutting off of the steam at any desired poi-nt of the stroke of thepiston. For instance, the same result and operation could be obtained ifthe true irregular portions between mand and c and Z were omittedaltogether and only the irregular or inclined portions of the grooveprovided. It is obvious that in such arrangement on the revolving of thedisk the inclined or irregular portions of the groove would alternatelyengage the roller 29, and hence actuate the pivoted plate 22,

.and when these irregular portions of the groove'leave the roller 29 thepivoted plate 22 would remain inactive.

For stopping altogether the operation of the valve or for reversing thedirection of rotation -of the crank-shaft and for regulating the degreeof movement of the valve I employ the lever 35. When this lever isadjusted to the central notchl of the bar 39, the link 2l is thrown sothat the roller 24 thereof is brought tol the center of the slot 25. Itwill be apparent that under this adjustment there is no rocking movementimparted to the link 21, and consequently the valve 10 is not actuated.When the lever 35 is thrown downwardly to the position shown in Fig. 1,the roller 24 is of course raised to the upper end of the slot 25, a-ndconsequently full movement is imparted to the link 21 and a fullactuation of the valve l0 thereby obtained. In order to reverse thedirection of rotation of the engine, all that is necessary to be done isto thrust the lever 35 upwardly above the central point, and the enginewill be thereby caused to rotate in the reverse direction.

It will be further apparent that gradations in the degree of movement ofthe valve in the running of the engine in eitheir direction may bereadily effected merely by adjusting the lever 35to certain positions inorder to bring the roller 24 varying degrees from the center of the slot25.

Besides the advantages already pointed out in vregard to my invention Iwould further call attention to the fact that the particularvconstruction thereof is such that a nunlber'of Wearing parte necessaryin the ordinary looothe other end of the roek-shaftand having its otherend guided by the longitudinal groove of the link, a lever pivoted tothe vertical Wall' and having a link connection with the firstnamedlever, and a notched bar on the vertical wall to retain the second-namedlever in its adjustments.

disk, a lever pivoted at one end to a crank on In testimony whereofIaiix my signature in presence of two Witnesses.

OSWALD JACKSON.

Witnesses:

' W. L. CLOSE,

H. H. MONTGOMERY.

